FORT MYERS, Fla. -- Outfielder Darin Mastroianni left Thursday's game against the Orioles in the fourth inning with a sore left hamstring and is day to day.

Mastroianni tweaked his hamstring on a check swing during his at-bat against Orioles right-hander Kevin Gausman. He still managed to hit a double that at-bat but was taken out for pinch-runner Clete Thomas.

Mastroianni, who is competing for the center-field job along with Aaron Hicks and Joe Benson, said he originally injured his hamstring in early December while playing in the Venezuelan Winter League. But he said the injury is only minor and that he was taken out for precautionary reasons.

"It's fine," said Mastroianni, who was 2-for-3 with a run scored in Thursday's 7-1 victory. "It's just something we've been working on down here. It's been lingering since I was in Venezuela. It's something that doesn't bother me when I'm running. It's only when I'm decelerating. It should be gone in a couple days, so I'm not worried about it."

Expecting twins, Mauer excited about fatherhood

FORT MYERS, Fla. -- It's only fitting that catcher Joe Mauer and his wife, Maddie, are expecting twins.

Mauer, who has spent his entire career with the Twins organization since being drafted by his hometown team as the No. 1 overall pick in the 2001 First-Year Player Draft, said he's excited about the prospect of being a father. The couple married in December and the twins are due in late August.

"It's unbelievable," Mauer said. "What a blessing. I'm just very excited and very happy. I really couldn't believe it at first. It's still kind of a shock. It's starting to hit me now that we're starting to tell people. I'm just very excited."

Mauer said he'll wait to find out about the gender of the fraternal twins but joked that it's killing his dad to know. Mauer added that his experience as an uncle will help, as his older brother Billy has three children and his older brother Jake, who manages the organization's Class A team in Cedar Rapids, Iowa, has two kids.

"I'll be doing it all," Mauer said with a smile. "I'm excited for it. I've seen how having kids have changed my brothers. So I've had practice with them. I'm looking forward to it."

Mauer, 29, is having himself another impressive Spring Training, hitting .375 (3-for-8) with a .615 on-base percentage in four games. He's set to leave Twins camp on Sunday for Arizona to join Team USA for the World Baseball Classic.

Meyer, Berrios post zeros in 'B' game

FORT MYERS, Fla. -- Twins pitching prospects Alex Meyer and Jose Berrios continued to impress by combining to throw four scoreless innings in a "B" game against the Red Sox on Thursday at JetBlue Park.

Meyer, ranked as the No. 40 overall prospect according to MLB.com, struck out three and gave up one hit in two scoreless frames. And Berrios, who is ranked as Minnesota's No. 9 prospect, threw two perfect innings in the Twins' 4-0 loss in seven innings.

"Meyer was really impressive," Twins manager Ron Gardenhire said. "It was the best performance for him down here. So we got our work in and the pitchers got some innings in."

They fared better than right-handers Samuel Deduno and B.J. Hermsen, who both struggled. Deduno, who is leaving the club this weekend to join Team Dominican Republic in the World Baseball Classic, gave up three runs on four hits in 1 2/3 innings.

Hermsen, the organization's Minor League Pitcher of the Year, surrendered a run in the final inning.

Prospects Aaron Hicks and Eddie Rosario each had a hit for the Twins, who didn't do much offensively against the Red Sox.

Hendriks picks up steam in strong outing

FORT MYERS, Fla. -- Right-hander Liam Hendriks came away pleased with his outing against the Orioles on Thursday, after he tossed three scoreless innings at Hammond Stadium.

Hendriks, in his second spring outing, improved his ERA to 1.80 ERA in Grapefruit League play by giving up just four hits. He's competing for a spot in the rotation after making 16 starts with a 5.59 ERA with the Twins and a 2.20 ERA in 16 starts at Triple-A Rochester last year.

"Good results are definitely nice, but sometimes you're trying to work on stuff, and today they both went hand in hand," Hendriks said. "So I think if I can execute the stuff I'm working on, I will do well. And today I felt pretty good about that and executed my game plan. It was good to get that three-inning [start] out of the way after not feeling so great in the second inning last time."

Twins manager Ron Gardenhire liked what he saw from Hendriks, who worked at a much better pace in his second outing.

"He was good," Gardenhire said. "He threw the ball well. He rushed a couple pitches here and there, but he settled in there and got his breaking ball where he wanted to. He got the outs when he had to and his pace was much better."